Wiper device for hard surfaces, in particular a window wiper

ABSTRACT

In order to reduce the energy consumption of the suction unit, on the one hand, and to improve the cleaning effect, on the other hand, of a wiper device for hard surfaces, in particular a window wiper, comprising a slit-shaped suction nozzle, on which a flexible wiper lip is arranged, which protrudes forwardly beyond the suction nozzle, it is suggested that the wiper lip be held on a wall of the suction nozzle and drawn against the opposite wall of the suction nozzle under the influence of a suction stream in the suction nozzle and thereby close the suction nozzle.

The invention relates to a wiper device for hard surfaces, in particulara window wiper, comprising a slit-shaped suction nozzle, a flexiblewiper lip being arranged on the nozzle and protruding forwardly beyondthe suction nozzle.

A window wiper of this type is known, for example, from German UtilityModel No. 80 19 169. In this case, a foamed rubber-type wiper pad islocated in a slit-like suction nozzle and, in addition, a wiper lip isarranged next to the wiper pad and independently of the slit nozzle. Thesuction effect in this known device is hindered by the foamedrubber-type wiper pad in the suction nozzle and so a suction unit havinga particularly high power capacity is necessary to maintain the requiredsuction stream.

The object of the invention is to improve a wiper device of the generictype such that the required suction capacity of the suction unit isreduced while, on the other hand, an improved wiping and cleaning actioncan be achieved. This object is accomplished in accordance with theinvention, in a wiper device for hard surfaces of the type described atthe outset, in that the wiper lip is held on a wall of the suctionnozzle and is drawn against the opposite wall of the suction nozzleunder the influence of a suction stream in the suction nozzle andthereby closes the suction nozzle.

In the new wiper device the suction nozzle is, therefore, normally openso that the suction stream can pass unhindered into the suction nozzle.As long as the wiper device rests on the window surface to be cleaned,the wiper lip is bent back such that the suction opening is opened. If,on the other hand, the wiper device is removed from the surface to becleaned, the suction stream now sucks the free wiper lip onto theopposite wall and thereby closes the suction opening. This has, on theone hand, the advantage that when the device is not in use and thesuction opening therefore closed the required suction capacity of asuction unit attached to the wiper device is reduced and, on the otherhand, liquid is reliably prevented from reaching the outside from theinterior of the wiper device, even when the user holds the wiper devicewith the suction nozzle facing downwards.

It is particularly advantageous for the wiper lip to project through thesuction nozzle, whereby it is preferably arranged in its undeformedstate between the two walls defining the suction nozzle. This means thatthe wiper lip can be bent up in one direction out of its undeformed restposition when it abuts on the surface to be cleaned whereas it is bentin the other direction, in which it closes the suction opening, when thewiper device is not in use and the suction unit is switched on. In apreferred embodiment, the wall mounting the wiper lip bears a supportsurface which extends towards the front edge of the wiper lip and onwhich the wiper lip abuts when it is deformed towards a complete openingof the suction nozzle. This means that the movement of the wiper lip islimited in opening position. The wiper lip, which rests on the surfaceto be cleaned with a front edge when it is drawn down this surface, issupported on the support surface in this way with its rear side so thatthe user can exactly meter the force with which the front edge of thewiper lip rests on the surface to be cleaned even though the wiper lipconsists of a flexible material.

In this respect, it is advantageous for the support surface to extendalmost as far as the front edge of the wiper lip.

The support surface is preferably curved convexly towards the front edgeof the wiper lip so that the wiper lip is not bent over sharply at anypoint. This promotes the flow properties of the suction stream in theregion of the suction opening; in this way turbulences in this regionare avoided.

The front edge of the support surface and the front edge of the oppositewall are preferably arranged approximately opposite one another. Theytherefore form the slit-like suction opening between them, whereby thesuction opening is constricted at one wall due to the wiper lip restingon the support surface. This construction makes it possible to exactlydefine the width of the gap between the front edge of the opposite walland the surface to be cleaned since the distance of the wiper device asa whole from the surface to be cleaned is determined by the front edgeof the support surface and the wiper lip. In this way, the suctionproperties in the region of the suction nozzle may be optimalized.

It is favorable for the walls adjoining the suction nozzle in thesuction direction to diverge in the suction direction. This results in aparticularly high suction velocity in the region of the suction nozzle.

In addition, the wiper device can bear next to the suction nozzle awiper pad extending parallel thereto, with which a cleaning liquidapplied to the surface to be cleaned can, if necessary, be distributedunder pressure and with which a mechanical precleaning of the surface tobe cleaned takes place.

It is particularly advantageous for the wiper pad to be arranged on thesame wall as the wiper lip. In this way, the wiper pad is located on theside remote from the surface to be cleaned when this surface is wipedand does not hinder the wiping procedure. In order to use the wiper pad,the wiper device is simply turned around so that the wiper pad thenpoints in the direction towards the surface to be cleaned.

It is advantageous when the wiper pad is adapted to be secured inposition in a holder arranged on the wall at various distances from thewall. In this way it is possible to replace the wiper pad, for examplewhen the use of wiper pads having different hardnesses is desired. Onthe other hand, ergonomic aspects may be taken into consideration in anoptimum manner when the wiper pad is arranged at varying distances fromthe wall of the wiper device. A particularly simple exchangeabilityresults when the wiper pad is insertable laterally into the holder.

In addition, it is favorable for the wiper device to have a spray nozzlefor applying a cleaning liquid to the surface to be cleaned, whereby thespray nozzle is preferably arranged on the same side as the wiper pad.It is then possible to add cleaning liquid as desired in a meteredmanner during cleaning of the surface with the wiper pad.

The spray nozzle can be releasably held in position in a slide-in holderand so as to be sealed relative to the wiper device so that it can beinterchanged simply and at any time by insertion or withdrawal. Thismeans that nozzles having different spray characteristics can be used,for example spot spraying nozzles for a powerful precleaning and flatspraying nozzles for an even application of the cleaning liquid to alarger area.

An actuating knob for the spray nozzle can be arranged on the side ofthe wiper device opposite the spray nozzle, whereby it is favorable fora switch element for switching on and off a suction unit generating thesuction stream to be arranged next to the actuating knob.

In order to be able to monitor the functioning of the wiper device andin order to be able to ascertain the degree of soiling of the liquidsucked off, the wiper device may be transparent at least in certainregions in the part lying downstream of the suction nozzle. In apreferred embodiment, an indicator element which is visible from theoutside and movable into various positions as a function of the force ofthe suction stream is arranged in the interior of the wiper device. Whena suction stream is absent, this may be detected quite easily due to thedifferent position of the indicator element in comparison with anoperative suction stream.

The wiper device can be widenable in the region of the suction nozzle byan extension element, in which the suction nozzle continues. In thisrespect, it is favorable for the wiper device to bear a removableclosure plate at its lateral end faces, the extension element beingattachable in its stead.

A telescopically extendable suction pipe may adjoin the suction nozzle.This pipe can, for example, be lockable in the extended position so thatit is drawn automatically into the shortened position when the lockedposition is released and the suction opening closed by the wiper lip.

The following description of preferred embodiments of the inventionserves to explain the invention in greater detail in conjunction withthe drawings. In the drawings:

FIG. 1: shows a longitudinal sectional view of a wiper device resting ona windowpane;

FIG. 2: is a plan view onto the front part of the wiper device of FIG.1;

FIG. 3: shows an enlarged longitudinal sectional view of the wiperdevice in the region of circle A in FIG. 1, with the suction streamswitched off;

FIG. 4: is a view similar to FIG. 3 with the suction stream switched onand the wiper device not resting against a surface to be cleaned

FIG. 5: is a view similar to FIG. 4 with the wiper device restingagainst a surface to be cleaned; and

FIG. 6: is a view of an alternate, telescoping embodiment of the suctionpipe.

The wiper device illustrated in the drawings is primarily intended forthe cleaning of windowpanes but is also suitable for cleaning other hardsurfaces.

The wiper device comprises a suction head 1 with a plane upper wall 2and a lower plane wall 4, which diverges at an acute angle from thefront edge 3 of the upper wall 2 and the front edge 5 of which forms aslit-like suction nozzle 6 with the front edge 3 of the upper wall 2. Atits lateral ends, the suction head 1 which is limited by the upper andthe lower wall 2 and 4, respectively, is limited by lateral wallportions 7 which are releasably attached to the walls 2 and 4, forexample by elastic snap-in engagement. In this way, the wall portions 7can be removed and in their stead lateral extension elements 8 can besealingly connected with the walls 2 and 4. These extension elements area lateral continuation of the suction head 1 and in this way widen thesuction head 1 and, in particular, the suction nozzle 6 (FIG. 2). Thewidth of the suction nozzle 6 can be varied in this manner, either bynot using any extension element or by adding extension elements to onlyone side or to both sides.

The suction head 1 limited by the walls 2 and 4 merges on the sideopposite the suction nozzle 6 into a suction pipe 9 which is sealinglymounted onto a connection piece 10 at the end of the suction head 1opposite the suction nozzle 6. The suction pipe 9, which is designed asa rigid piece of pipe in the illustrated embodiment, can also comprise atelescoping pipe consisting of several pipe sections 9a, 9b and 9c, asillustrated in FIG. 6.

The suction pipe 9 is connected to a flexible suction tube 11 whichleads to a suction unit in a manner not apparent from the drawing. Thissuction unit is preferably operated via its own battery but it can alsobe supplied via an electric supply cable, for example, from the batteryof a motor vehicle. In order to switch the suction unit on and off, acontrol line 12 is provided which leads along the suction tube 11 andthe suction pipe 9 to a switch 13 in the suction pipe 9. This switch 13is preferably designed as a push button so that the suction unitoperates while pressure is exerted on the switch 13 but switches offwhen the switch is released.

Furthermore, a pump may be located next to the suction unit to transporta cleaning liquid from a supply vessel via a supply line 14 to a spraynozzle 15 which is located in the upper wall 2 in the immediate vicinityof the connection piece 10. This spray nozzle can be securely connectedto the upper wall 2; in a preferred embodiment it is insertably held ina corresponding holder, whereby a seal is provided between the spraynozzle and the upper wall 2 via sealing means not illustrated in thedrawing. In such a construction, the spray nozzle can be interchanged ina simple manner.

The pump can be switched on and off via an additional switch 16 which isarranged on the suction pipe 9 next to the switch 13. This switch 16 isalso preferably designed as a push button.

The control line 12 and the supply line 14 may extend in the interior ofthe suction tube 11 but provision may be made for them to exit from thesuction pipe at the transition from the suction pipe 9 to the suctiontube 11 so that the suction pipe is freely rotatable in relation to thesuction tube.

Apart from the supply vessel, a collecting vessel is also associatedwith the suction unit and liquid sucked through the suction tube 11 iscollected therein. A particularly favorable design results when thesupply vessel for the cleaning liquid and the collecting vessel for thesoiled liquid are located in a common container which is divided intotwo corresponding chambers by a flexible intermediate wall. This meansthat the entire container is available at the beginning of the cleaningprocess for the cleaning liquid, after termination of the cleaningprocess for the dirty, collected liquid.

A central region 17 of the upper wall is designed to be transparent andtherefore forms a window, through which the interior of the suction head1 can be viewed and it can be ascertained whether liquid is being suckedthrough and, if necessary, the degree of soiling of such liquid.Moreover, it is possible to see an indicator element 18, which ispivotally mounted in the interior of the suction head 1, through thistransparent region 17. This element has a wing-type profile and istherefore pivoted by the suction stream into a horizontal position, asis apparent from FIG. 1. If the suction stream is lacking, the indicatorelement 18 will, on the other hand, hang downwards. These differentpositions can be detected from the outside, for example, due to the factthat in the horizontal case a colored surface of the indicator element18 is to be seen directly beneath the transparent upper wall 2 but, onthe other hand, when the suction stream is absent this surface is not tobe seen. This results in an indicator element which indicates thepresence of a suction stream and, if necessary, the force thereof, aswell.

A holder 19 for an elongated wiper pad 20 is located on the upper wall2, extending parallel to the front edge 3 and at a slight distancetherefrom. This wiper pad can, for example, have a circular crosssection and consist of foamed rubber which is secured in a bar 21U-shaped in cross section. This bar 21 has laterally protrudingprojections 22 for insertion into opposite grooves 23 of two parallelwalls 24 and 25 of the holder 19 (FIG. 1). A plurality of grooves 23 ofthis type are provided one above the other in the walls 24 and 25 sothat the bar 21 can be inserted at varying distances in relation to theupper wall 2. In this way, the wiper pad 20 can also be arranged atvarying distances in relation to the upper wall 2 of the suction head 1.The bar with the wiper pad can be removed quite easily by lateraldisplacement so that the wiper pad can be exchanged as desired. Aretaining bar 26 for a strip-like wiper lip 27, which consists of aflexible material, for example of rubber, is arranged on the inner sideof the upper wall 2 in the region of the suction nozzle 6. This wiperlip 27 is inserted laterally into a corresponding recess 29 of theretaining bar 26 with a rear edge 28 thickened in the form of a bead,whereby the wiper lip 27 passes through a slot 30 which exits from therecess 29 essentially parallel to the upper wall 2. In this way, thewiper lip 27 is secured against any displacement in the longitudinaldirection.

The slot 30 is arranged such that the undeformed wiper lip 27 exitingtherefrom and extending parallel to the upper wall 2 is arrangedapproximately between this wall and the front edge 5 of the lower wall 4(FIG. 3). In this respect, the wiper lip 27 protrudes slightly beyondthe front edge 3 of the upper wall 2 whereas the front edge 5 of thelower wall 4 is set back somewhat in relation thereto. The wiper lip 27terminates at its free end with a rectangular cross section, i.e. asharp front edge 31 results on the underside of the wiper lip.

The underside 32 of the retaining bar 26 is designed to be parallel tothe lower wall 4 in the part located downstream of the slot 30.Underside 32 provides a support surface 33 between the slot 30, on theone hand, and the front edge 3 of the upper wall 2, on the other hand.Support surface 33 is slightly curved convexly. The underside 32 isuniformly profiled along the entire length of the holder bar 26.

During operation, the wiper device described is used first of all tospray the surface to be cleaned with a cleaning liquid. For thispurpose, the spray nozzle 15 is directed onto the surface to be cleaned,and by actuating the switch 16 the supply of cleaning liquid is switchedon. Cleaning chemicals can be added to the cleaning liquid.

After the cleaning liquid has been applied, the surface to be cleaned iscleaned with the aid of the wiper pad 20, whereby stubborn dirt can alsobe mechanically loosened by applying a corresponding pressure.

In a next operation step, the wiper device is turned over so that thewiper pad 20 points upwards in the manner apparent from FIG. 1. Thewiper device is applied to the surface 34 to be cleaned with the wiperlip 27; at the same time the suction unit is switched on by actuatingthe switch 13, i.e. a suction stream is generated in the suction head 1,due to which surrounding air is sucked in via the suction nozzle 6.

Before the wiper lip 27 is applied to the surface 34 to be cleaned, thesuction nozzle 6 is still closed and an opening does not result untilthe wiper lip 27 rests against the surface 34 to be cleaned and is bentupwards, i.e. rests against the support surface 33, due to movement ofthe entire suction head 1 downwards (FIG. 5). In this position, which iscaused by the downwardly directed wiping action of the suction head 1,the cleaning liquid is sucked into the suction head 1 from the surface34 through the suction opening 6 which is then open; at the same timethe sharp front edge 31 of the wiper lip 27 slides along the surface 34and wipes cleaning liquid quantitatively off the surface 34. Following asingle wiping stroke the surface is completely free from cleaningliquid. Once the wiper device has been removed from the surface 34, thewiper lip 27 is sucked against the front edge 5 of the lower wall 4(FIG. 4) due to the action of the suction stream so that the suctionnozzle 6 is closed.

On the one hand, this means that the power required by the electromotordriving the suction unit is reduced, i.e. motive energy is saved; on theother hand, it is ensured that even when the wiper device is held suchthat the nozzle points downwardly, no sucked-in cleaning liquid can runout of it.

A quite particular advantage of this automatically occurring closure ofthe suction opening is to be seen in the fact that the suction nozzle 6is opened only in that section in which the wiper lip 27 abuts againstthe support surface 33 when the wiper lip is applied to the surface 34.When the surface 34 to be cleaned is uneven, only those portions of thewiper lip 27 that traverse raised areas of the surface will bend, andthe suction nozzle 6 will be opened only in those portions to provide aneffective wiping action. For those portions of the wiper lip 27 that donot abut on the surface 34, and therefore do not generate any wipingaction, the suction nozzle 6 remains closed so that no undesired bypassresults at these points. The sucking action is therefore concentrated onthose regions in which cleaning liquid is effectively wiped off.

An additional advantage of the arrangement described is to be seen inthe fact that the support surface 33 supports the wiper lip 27essentially over its entire length, i.e., in particular, in a regionwhich is located opposite the front edge 31, as well. This means that itis possible to press this front edge against the surface 34 with anexactly metered pressure, despite the flexible design of the wiper lip27, and therefore to meter the wiping off action.

We claim:
 1. A wiper device for a hard surface comprising:a slit-shapedsuction nozzle having a first wall on a first side of the wiper deviceand an opposite wall on a second side of the wiper device; a flexiblewiper lip arranged on one of said walls and protruding beyond saidsuction nozzle; a wiper pad extending from one of said first and secondsides of said wiper device adjacent to and extending parallel to saidsuction nozzles, wherein said wiper pad is located to be entirely out ofcontact with a suction stream drawn through said suction nozzle; and aspray nozzle for applying a cleaning liquid to a surface to be cleaned,said spray nozzle being mounted on the same side of said wiper device assaid wiper pad but separate from said wiper pad to enable said cleaningliquid to be applied from the spray nozzle to said surface to be cleanedindependently of said wiper pad.
 2. A wiper device as defined in claim1, wherein the wiper lip projects through the suction nozzle.
 3. A wiperdevice as defined in claim 2, wherein the wiper lip is arranged in itsundeformed state between said first and opposite walls defining thesuction nozzle.
 4. A wiper device as defined in claim 1, wherein saidwiper lip has a front edge, and the first wall bears a support surfaceextending towards said front edge of the wiper lip, the wiper lipabutting said support surface when it is deformed towards said firstwall to completely open the suction nozzle.
 5. A wiper device as definedin claim 4, wherein the support surface extends almost as far as thefront edge of the wiper lip.
 6. A wiper device as defined in claim 4,wherein the support surface is curved convexly towards the front edge ofthe wiper lip.
 7. A wiper device as defined in claim 4, wherein saidsupport surface and opposite wall each have front edges, the front edgeof the support surface and the front edge of said opposite wall beingarranged approximately opposite one another.
 8. A wiper device asdefined in claim 1, wherein said first and opposite walls diverge awayfrom said suction nozzle.
 9. A wiper device as defined in claim 1,wherein the wiper pad is arranged on the same wall as the wiper lip. 10.A wiper device as defined in claim 1, wherein said first wall comprisesa holder for said wiper pad, and the wiper pad is adapted to be securedin position in said holder at various distances from the first wall. 11.A wiper device as defined in claim 10, wherein said holder has an endfor receiving said wiper pad, the wiper pad being insertable into saidholder via said end.
 12. A wiper device as defined in claim 1, furthercomprising a slide-in holder for releasably securing the spray nozzle,said slide-in holder sealingly engaging the wiper device.
 13. A wiperdevice as defined in claim 1, wherein an actuating knob for the spraynozzle is arranged on the side of the wiper device opposite the spraynozzle.
 14. A wiper device as defined in claim 13 further comprising asuction unit for generating a suction stream, wherein a switch elementis arranged next to the actuating knob for switching said suction uniton and off.
 15. A wiper device as defined in claim 1, wherein the deviceis transparent at least in certain regions downstream of the suctionnozzle.
 16. A wiper device as defined in claim 1, further comprising anindicator element arranged in the interior of said suction nozzle, saidindicator element being visible from the outside of said device andmovable into various positions as a function of the force of a suctionstream being drawn through the suction nozzle.
 17. A wiper device asdefined in claim 1, further comprising an extension element for wideningthe suction nozzle.
 18. A wiper device as defined in claim 17, saidwiper device having a lateral end face and further comprising aremovable closure plate at said lateral end face, the removal of saidclosure plate enabling the attachment of said extension element.
 19. Awiper device as defined in claim 1 further comprising a telescopicallyextendable suction pipe adjoining the suction nozzle.
 20. A wiper devicefor a hard surface comprising:a slit-shaped suction nozzle having afirst wall on a first side of the wiper device and an opposite wall on asecond side of the wiper device; a flexible wiper lip arranged on one ofsaid walls and protruding beyond said suction nozzle such that a suctionstream drawn through said suction nozzle will deflect said wiper lip toclose said nozzle, said wiper lip having a front edge and said firstwall bearing a support surface extending towards said front edge andbeing curved convexly towards the front edge of the wiper lip, with saidwiper lip abutting said support surface when it is deformed towards saidfirst wall to completely open the suction nozzle; a wiper pad extendingfrom one of said first and second sides of said wiper device adjacent toand extending parallel to said suction nozzle; and a spray nozzle forapplying a cleaning liquid to a surface to be cleaned, said spray nozzlebeing mounted on the same side of said wiper device as said wiper pad.21. A wiper device for a hard surface comprising:a slit-shaped suctionnozzle having a first wall on a first side of the wiper device and anopposite wall on a second side of the wiper device; a flexible wiper liparranged on one of said walls and protruding beyond said suction nozzlesuch that a suction stream drawn through said suction nozzle willdeflect said wiper lip to close said nozzle; a wiper pad extending fromone of said first and second sides of said wiper device adjacent to andextending parallel to said suction nozzle; a spray nozzle for applying acleaning liquid to a surface to be cleaned, said spray nozzle beingmounted on the same side of said wiper device as said wiper pad; and aslide-in holder for releasably securing said spray nozzle, said slide-inholder sealingly engaging the wiper device.
 22. A wiper device for ahard surface comprising:a slit-shaped suction nozzle having a first wallon a first side of the wiper device and an opposite wall on a secondside of the wiper device; a flexible wiper lip arranged on one of saidwalls and protruding beyond said suction nozzle such that a suctionstream drawn through said suction nozzle will deflect said wiper lip toclose said nozzle; a wiper pad extending from one of said first andsecond sides of said wiper device adjacent to and extending parallel tosaid suction nozzle; a spray nozzle for applying a cleaning liquid to asurface to be cleaned, said spray nozzle being mounted on the same sideof said wiper device as said wiper pad; and an actuating knob for saidspray nozzle, said actuating knob being arranged on the side of saidwiper device opposite the spray nozzle.
 23. A wiper device as defined inclaim 22, further comprising a suction unit for generating said suctionstream, wherein a switch element for switching said suction unit on andoff is arranged next to said actuating knob.
 24. A wiper device for ahard surface comprising:a slit-shaped suction nozzle having a first wallon a first side of the wiper device and an opposite wall on a secondside of the wiper device; a flexible wiper lip arranged on one of saidwalls and protruding beyond said suction nozzle such that a suctionstream drawn through said suction nozzle will deflect said wiper lip toclose said nozzle; a wiper pad extending from one of said first andsecond sides of said wiper device adjacent to and extending parallel tosaid suction nozzle; a spray nozzle for applying a cleaning liquid to asurface to be cleaned, said spray nozzle being mounted on the same sideof said wiper device as said wiper pad; wherein said wiper device istransparent at least in certain regions downstream of said suctionnozzle.
 25. A wiper device for a hard surface comprising:a slit-shapedsuction nozzle having a first wall on a first side of the wiper deviceand an opposite wall on a second side of the wiper device; a flexiblewiper lip arranged on one of said walls and protruding beyond saidsuction nozzle such that a suction stream drawn through said suctionnozzle will deflect said wiper lip to close said nozzle; a wiper padextending from one of said first and second sides of said wiper deviceadjacent to and extending parallel to said suction nozzle; a spraynozzle for applying a cleaning liquid to a surface to be cleaned, saidspray nozzle being mounted on the same side of said wiper device as saidwiper pad; and an indicator element arranged in the interior of saidsuction nozzle, said indicator element being visible from the outside ofsaid device and movable into various positions as a function of theforce of said suction stream.
 26. A wiper device for a hard surfacecomprising:a slit-shaped suction nozzle having a first wall on a firstside of the wiper device and an opposite wall on a second side of thewiper device; a flexible wiper lip arranged on one of said walls andprotruding beyond said suction nozzle such that a suction stream drawnthrough said suction nozzle will deflect said wiper lip to close saidnozzle; a wiper pad extending from one of said first and second sides ofsaid wiper device adjacent to and extending parallel to said suctionnozzle; a spray nozzle for applying a cleaning liquid to a surface to becleaned, said spray nozzle being mounted on the same side of said wiperdevice as said wiper pad; and an extension element for widening saidsuction nozzle.
 27. A wiper device as defined in claim 26, said wiperdevice having a lateral end face and further comprising a removableclosure plate at said lateral end face, the removal of said closureplate enabling the attachment of said extension element.
 28. A wiperdevice for a hard surface comprising:a slit-shaped suction nozzle havinga first wall on a first side of the wiper device and an opposite wall ona second side of the wiper device; a flexible wiper lip arranged On oneof said walls and protruding beyond said suction nozzle such that asuction stream drawn through said suction nozzle will deflect said wiperlip to close said nozzle; a wiper pad extending from one of said firstand second sides of said wiper device adjacent to and extending parallelto said suction nozzle; a spray nozzle for applying a cleaning liquid toa surface to be cleaned, said spray nozzle being mounted on the sameside of said wiper device as said wiper pad; and a telescopicallyextendable suction pipe adjoining said suction nozzle.
 29. A wiperdevice for a hard surface comprising:a slit-shaped suction nozzleopening of said having a first wall on a first side of the wiper deviceand an opposite wall on a second side of the wiper device; a flexiblewiper lip arranged on one of said walls and protruding beyond saidsuction nozzle, said wiper lip projecting through said suction nozzle; awiper pad extending from one of said first and second sides of saidwiper device adjacent to and extending parallel to said suction nozzle;and a spray nozzle for applying a cleaning liquid to a surface to becleaned, said spray nozzle being mounted on the same side of said wiperdevice as said wiper pad but separate from said wiper pad to enable saidcleaning liquid to be applied from the spray nozzle to said surface tobe cleaned independently of said wiper pad.
 30. A wiper device for ahard surface comprising:a slit-shaped suction nozzle having a first wallon a first side of the wiper device and an opposite wall on a secondside of the wiper device; a flexible wiper lip arranged on one of saidwalls and protruding beyond said suction nozzle; a wiper pad extendingfrom one of said first and second sides of said wiper device adjacent toand extending parallel to said suction nozzle; and a spray nozzle forapplying a cleaning liquid to a surface to be cleaned, said spray nozzlebeing mounted on the same side of said wiper device as said wiper padbut separate from said wiper pad to enable said cleaning liquid to beapplied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; wherein said first wall bears a supportsurface extending towards a front edge of the wiper lip, the wiper lipabutting said support surface when it is deformed towards said firstwall to completely open the suction nozzle, said support surface beingcurved convexly towards the front edge of the wiper lip.
 31. A wiperdevice for a hard surface comprising:a slit-shaped suction nozzle havinga first wall on a first side of the wiper device and an opposite wall ona second side of the wiper device; a flexible wiper lip arranged on oneof said walls and protruding beyond said suction nozzle; a wiper padextending from one of said first and second sides of said wiper deviceadjacent to and extending parallel to said suction nozzle; and a spraynozzle for applying a cleaning liquid to a surface to be cleaned, saidspray nozzle being mounted on the same side of said wiper device as saidwiper pad but separate from said wiper pad to enable said cleaningliquid to be applied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; wherein said first and opposite wallsdiverge away from said suction nozzle.
 32. A wiper device for a hardsurface comprising:a slit-shaped suction nozzle having a first wall on afirst side of the wiper device and an opposite wall on a second side ofthe wiper device;, a flexible wiper lip arranged on one of said wallsand protruding beyond said suction nozzle; a wiper pad extending fromone of said first and second sides of said wiper device adjacent to andextending parallel to said suction nozzle; and a spray nozzle forapplying a cleaning liquid to a surface to be cleaned, said spray nozzlebeing mounted on the same side of said wiper device as said wiper padbut separate from said wiper pad to enable said cleaning liquid to beapplied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; wherein the wiper pad is arranged onthe same wall as the wiper lip.
 33. A wiper device for a hard surfacecomprising:a slit-shaped suction nozzle having a first wall on a firstside of the wiper device and an opposite wall on a second side of thewiper device; a flexible wiper lip arranged on one of said walls andprotruding beyond said suction nozzle; a wiper pad extending from one ofsaid first and second sides of said wiper device adjacent to andextending parallel to said suction nozzle; and a spray nozzle forapplying a cleaning liquid to a surface to be cleaned, said spray nozzlebeing mounted on the same side of said wiper device as said wiper padbut separate from said wiper pad to enable said cleaning liquid to beapplied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; wherein the wiper pad is adapted to besecured in position in a holder arranged on the first wall at variousdistances from the first wall.
 34. A wiper device for a hard surfacecomprising:a slit-shaped suction nozzle having a first wall on a firstside of the wiper device and an opposite wall on a second side of thewiper device; a flexible wiper lip arranged on one of said walls andprotruding beyond said suction nozzle; a wiper pad extending from one ofsaid first and second sides of said wiper device adjacent to andextending parallel to said suction nozzle; and a spray nozzle forapplying a cleaning liquid to a surface to be cleaned, said spray nozzlebeing mounted on the same side of said wiper device as said wiper padbut separate from said wiper pad to enable said cleaning liquid to beapplied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; wherein the device is transparent anleast in certain regions downstream of the suction nozzle.
 35. A wiperdevice for a hard surface comprising:a slit-shaped suction nozzle havinga first wall on a first side of the wiper device and an opposite wall ona second side of the wiper device; a flexible wiper lip arranged on oneof said walls and protruding beyond said suction nozzle; a wiper padextending from one of said first and second sides of said wiper deviceadjacent to and extending parallel to said suction nozzle; a spraynozzle for applying a cleaning liquid to a surface to be cleaned, saidspray nozzle being mounted on the same side of said wiper device as saidwiper pad but separate from said wiper pad to enable said cleaningliquid to be applied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; and an indicator element arranged inthe interior of said wiper device, said indicator element being visiblefrom the outside of said device and movable into various positions as afunction of the force of a suction stream.
 36. A wiper device for a hardsurface comprising:a slit-shaped suction nozzle having a first wall on afirst side of the wiper device and an opposite wall on a second side ofthe wiper device; a flexible wiper lip arranged on one of said walls andprotruding beyond said suction nozzle; a wiper pad extending from one ofsaid first and second sides of said wiper device adjacent to andextending parallel to said suction nozzle; a spray nozzle for applying acleaning liquid to a surface to be cleaned, said spray nozzle beingmounted on the same side of said wiper device as said wiper pad butseparate from said wiper pad to enable said cleaning liquid to beapplied from the spray nozzle to said surface to be cleanedindependently of said wiper pad; and an extension element for wideningthe suction nozzle.
 37. A wiper device for a hard surface comprising:aslit-shaped suction nozzle having a first wall on a first side of thewiper device and an opposite wall on a second side of the wiper device;a flexible wiper lip arranged on one of said walls and protruding beyondsaid suction nozzle; a wiper pad extending from one of said first andsecond sides of said wiper device adjacent to and extending parallel tosaid suction nozzle; a spray nozzle for applying a cleaning liquid to asurface to be cleaned, said spray nozzle being mounted on the same sideof said wiper device as said wiper pad but separate from said wiper padto enable said cleaning liquid to be applied from the spray nozzle tosaid surface to be cleaned independently of said wiper pad; and atelescopically extendable suction pipe adjoining the suction nozzle.